1. Field of the Invention
The present invention relates to a developing cartridge attachable to and detachable from an image forming apparatus body, and to an image forming apparatus.
Note that the image forming apparatus includes an electrophotographic copier, an electrophotographic printer (e.g., a laser beam printer and an LED printer), a facsimile apparatus and a wordprocessor etc.
2. Related Background Art
As a construction of an apparatus for forming a multi-color image based on an electrophotographic system, there has hitherto been proposed a method of obtaining the multicolor image by forming a latent image through a selective exposure to a drum-like electrophotographic photosensitive body (which is hereinafter referred to as a photosensitive drum) uniformly charged by a charging device, disposing a plurality of developing cartridges containing developers each assuming a different color on rotation selecting mechanism, developing while making the developing cartridge containing developer of a predetermind color assuming the predetermined color face to the photosensitive drum, transferring this developed image onto a recording medium, and further executing a developing and transferring process with respect to each color.
What has been utilized in recent years is that a drum cartridge structured to integrally include the photosensitive drum, a charging device and a cleaning member and so on defined as expendable units, and a developing cartridge accommodating developers and a developing unit, are so constructed as to be attachable to and detachable from the image forming apparatus, thus facilitating a user's maintenance operation such as replacing the parts.
In the above construction, however, when the development is effected or when the developing cartridge is moved by a rotation selecting mechanism, the floating developers within the image forming apparatus body might be adhered to the developing cartridge to contaminate it in some cases. Hence, there might arise a possibility in which the user, when performing the maintenance operation such as replacing the developing device, has to replace the developing cartridge adhered with the developers.